Said Farahat

• Ph.D. (Professor)
• Head of Faculty at University of Sistan and Baluchestan

This research aims to conduct a numerical analysis of the effect of geometrical and injection parameters on the skin friction coefficient in Taylor-Couette flow. Two concentric cylinders and cones are chosen for this purpose, with the inner one rotating and the outer one fixed. The relevant equations are solved using FLUENT software for three-dimen...

This study presents a new dynamic modeling of a vehicle by considering the engine dynamics. By selecting the vehicle coordinate system as the reference frame, all the force-torque equations of the sprung mass and unsprung masses are derived in this coordinate system by using the Newton’s equations of motion. Unlike the previous researches, in this...

In this study, the vehicle's dynamic behavior during braking and steering input is investigated by considering the quarter-car model. The case study for this research is a Sport-Utility Vehicle (SUV) with the anti-lock braking system (ABS) and nonlinear dynamic equations are considered for it along with Pacejka tire model. Regulating the wheel slip...

Considering the reduction of fossil fuel resources and the increase of environmental pollutions, everyone is aware of the importance of saving on consumption of energies generated from fossil fuels. Global statistics demonstrates that 30–40% of the energy across different countries worldwide is used in residential buildings. Therefore, one way of e...

Residential and commercial buildings consume approximately 60% of the world’s electricity. It is almost impossible to provide a general definition of thermal comfort, because the feeling of thermal comfort is affected by varying preferences and specific traits of the population living in different climate zones. Considering that no studies have bee...

Residential and commercial buildings consume approximately 60% of the world’s electricity. It is almost impossible to provide a general definition of thermal comfort, because the feeling of thermal comfort is affected by varying preferences and specific traits of the population living in different climate zones. A few studies have been conducted on...

The primary purpose of present work is to evaluate and optimize the internal reversible combined cycle in operational conditions. Therefore, the effects of finite heat transfer are considered in different heat exchangers. In this study, the problem of the irreversible combined cycle is discussed by different heat exchangers. The total power of the...

The main purpose of this research is the thermodynamic analysis of the trigeneration system based on energy efficiency, exergy efficiency, and power. The trigeneration system under study consists of three subsystems that including the solar subsystem, Kalina subsystem, and lithium bromide-water absorption chiller subsystem. The proposed system gene...

Due to low energy price, economic optimization of consumption has no justification for users in Iran. Nowadays, the issue of ending fossil fuels, production of greenhouse gases and the main role of building in consumption of considerable amount of energy has drawn the focus of global researches to a new concept called net zero energy building. In t...

In this paper, a numerical and experimental analysis of the ventilated super-cavitating flow around a cone cavitator is presented. For the first time, the experiments are conducted in an open loop water tunnel. The fluid flow velocity in the test section is between 24 and 37 m/s at a constant rate of injection. The simulations of ventilated superca...

In this study, the optimal performance of a regenerative closed Brayton cycle is sought through power maximization. Optimization is performed on the output power as the objective function using genetic algorithm. In order to take into account the time and the size constraints in current problem, the dimensionless mass-flow parameter is used. The in...

Experiences have shown that creating a super-cavitating flows over underwater projectiles can significantly reduce their drag forces and change their dynamical behaviors. So the extended issues of this problem have been studied by researchers in the recent decades. In this paper, the geometrical characteristics of super-cavities, developed downstre...

In this study, the performance of an irreversible regenerative Brayton cycle is sought through power maximizations using finite-time thermodynamic concept in finite-size components. Optimizations are performed using a genetic algorithm. In order to take into account the finite-time and finite-size concepts in the current problem, a dimensionless ma...

This paper presents dynamical modeling and robust control of a Mini Unmanned Underwater Vehicle (MUUV) equipped with a new arrangement of water jet propulsion. The water jet propulsion includes some advantages comparing with a propeller one, such as, reducing the number of required motors, desired number and arrangement of the propulsions, removing...

It has been shown that developing a supercavitating flow around under-water projectiles has a significant effect on their drag reduction. As such, it has been a subject of growing attention in the recent decades. In this paper, a numerical and experimental study of supercavitating flows around axisymmetric cavitators is presented. The experiments a...

An approach for the optimization of laminar flow in diffusers is presented. The goal in our optimization process is to maximize diffuser performance and, in this way, pressure recovery by optimizing the geometry. Our methodology is the optimization through wall contouring of a given two-dimensional diffuser length ratio. The developed algorithm use...

In this study, the optimal performance of a regenerative Brayton cycle is sought through power maximization and then exergoeconomic optimization using finite-time thermodynamic concept and finite-size components. Optimizations are performed using genetic algorithm. In order to take into account the finite-time and finite-size concepts in current pr...

In this study, the nonlinear dynamic equation of unmanned underwater vehicle (UUV) with new propulsion arrangement is derived using robotics and dynamics techniques. Then, an optimal robust controller is designed to control the UUV. The uncertainty of extracted model is a problem dealing with model based controllers usually. The extracted hydrodyna...

In this work, the fluid flow in a direct injection compression ignition engine and its effects on performance and pollutant emissions are studied by using computational fluid dynamics simulation through developing of variable valve timing system by combination of the optimum valve lifting and late inlet valve closing (LIVC) strategies. For this pur...

In this research, generation of a short and smooth path in three-dimensional space with obstacles for guiding an Unmanned Underwater Vehicle (UUV) without collision is investigated. This is done by utilizing spline technique, in which the spline control points positions are deter-mined by Imperialist Competitive Algorithm (ICA) in three-dimensional...

Vehicles play an important role in transportation. Using fossil fuels as their source of energy, they are a source of pollution. HEVs are improving and a day will come that they will take over the role of conventional vehicles. In the path of improving HEVs, optimizing components sizes of the vehicle and better strategy controls are vital methods t...

p>In this project we study a kind of scanner in micro dimensions in which it includes three frames also the third frame is considered as fixed surface and the two others are including two separate coils that electric current enters it and when we expose this electric current in a magnetic field under a specific conditions then with the use of Loren...

Small bubble experiments are carried out in a circulating vertical Couette–Taylor flow system to investigate the effect of air bubbles on head resistance. In the system with inner rotating cylinder and circulating flow, flow is combined with circumferential and axial flow. Moreover, the variation range of rotational Reynolds number is \(7 \times 10...

Iran has a great potential for wind energy. This paper introduces optimization of 7 wind turbine blades for small and medium scales in a determined wind condition of Zabol site, Iran, where the average wind speed is considered 7 m /s. Considered wind turbines are 3 bladed and radius of 7 case study turbine blades are 4.5 m, 6.5 m, 8 m, 9 m, 10 m, 1...

Some of the major hydropower plants calculations are turbine type selection, speed and diameter of runner, dimensions of draft tube and spiral case. Since manufacturers have their own professional softwares, educator and consultant engineers have to use commercial softwares or mathematical methods and rely on their results for estimation and prelim...

Purpose – The purpose of this paper is to find the optimum design of diffuser of supersonic wind tunnel in order to access the minimum overall pressure drop in wind tunnel, using evolutionary algorithm. Design/methodology/approach – The authors developed a genetic algorithm (GA) code to calculate the shape of a diffuser with flexible walls in orde...

In this study, the optimal performance of a regenerative Brayton cycle is sought through power and then ecological function maximization using finite-time thermodynamic concept and finite-size components. Multi-objective optimization is used for maximizing the ecological function. Optimizations are performed using genetic algorithm. In order to tak...

In this paper, frictional drag reduction by small bubbles is studied experimentally on shear flow between co-axial cylinders in a Couette-Taylor system. In this system, the internal cylinder is rotatory while the outer cylinder is stationary. A porous body is used to produce small bubbles, and to avoid the uncertain interfacial property of bubbles,...

In the present paper, the effect of combined cooling, heating and power generation systems(CCHP) in the reduction of pollutants emission has been investigated and hotel with 80 rooms in Zahedan has been selected as case study, also gas engine (with part-load operation) as prime mover for designed CCHP system. In this work it is assumed that selli...

In recent years, most of researchers attempt to replace manpower with robots because of their ability to do repetitive work and also their accuracy in critical condition. Unmanned Aerial Vehicles (UAVs) are attained more attention for their advantages rather than other kind of manned aerial vehicles (MAVs). Quadrotor is a special kind of UAVs with...

In this study a safe and smooth path planning containing the slightest risk is considered for an Unmanned Underwater Vehicle (UUV). To do so, three smooth and continuous functions resembling the three dimensional path are introduced and then their parameters are optimized using the particle swarm optimization method to find the safest possible path...

This paper propose a new method for designing a stand-alone hybrid wind-PV-diesel-battery (WPDB) system that minimizes the inequality coefficient (IC), annualized cost of system (ACS), and maximizes correlation coefficient (CC) using multi-objective particle swarm optimization (MOPSO) algorithm. The proposed method uses data from solar radiation, t...

The effect of axial flow on bubbly drag reduction has been experimentally investigated in a vertical Couette–Taylor flow system. The water flow is combined from circumferential and axial flow. Flow condition is fully turbulence and Taylor vortices have appeared in the annulus gap. The shear stress modification in the simultaneous presence of air bu...

In this paper, the optimization of a solar photovoltaic thermal (PV/T) water collector which is based on exergy concept is carried out. Considering energy balance for different components of PV/T collector, we can obtain analytical expressions for thermal parameters (i.e. solar cells temperature, outlet water temperature, useful absorbed heat rate,...

در این پژوهش با ارایه روشی ساده جهت پیاده سازی سیستم ترمز بازیافتی در یک خودروی هیبریدی موازی پرداخته می¬شود. مطالعه ی موردی خودروی پراید SX _ 132 بوده که توسط موتور الکتریکی DC (continuous) 11.5Kwهیبریدی"موازی" شده است.

The effect of axial flow on bubbly drag reduction has been experimentally investigated in a vertical Couette–Taylor flow system. The water flow is combined from circumferential and axial flow. Flow condition is fully turbulence and Taylor vortices have appeared in the annulus gap. The shear stress modification in the simultaneous presence of air bu...

Drawing on effective experiments and measurement technology, the present study seeks to discuss the interaction between liquid turbulent boundary layer and a crowded group of small bubbles. Experiments are carried out using a circulating water Couette–Taylor system especially designed for small bubble experiments. Couette–Taylor system has a detail...

Drawing on effective experiments and measurement technology, the present study seeks to discuss the interaction between liquid turbulent boundary layer and a crowded group of small bubbles. Experiments are carried out using a circulating water Couette–Taylor system especially designed for small bubble experiments. Couette–Taylor system has a detail...

The presence of free convective heat transfer in an enclosure filled with a congealing melt leads to the output of a product with a nonuniform structure involving large grains. On applying a proper magnetic field to the melt in the enclosure, the convective flows are decreased and uniform and small grain structures are obtained. In this work, using...

Design of sustainable energy systems for the supply of electricity need correct selection and sizing to reduce investment costs. In this article, a new sizing methodology is developed for stand-alone hybrid wind/photovoltaic (PV) power systems, using multi-objective optimisation algorithms. Multi-objective particle swarm optimisation algorithm and...

Solar air heater requires investigation for enhancement of solar energy conversion into heat. Different configurations with various artificial roughness geometries are proposed to date. In present study attention is paid on ways leading to more delivery of exergy by a v-corrugated solar air heater through parametric study. Effects of aspect ratio o...

The aim of the present study is the simultaneous optimization of thermal and electrical efficiencies of a solar photovoltaic thermal (PV/T) air collector. The analytical expressions for thermal parameters and thermal efficiency are derived by developing energy balance equation for each component of PV/T air collector. In order to calculate the elec...

In this paper, an attempt is made to develop a thermal and electrical model for an integrated solar photovoltaic thermal (PV/T) water collector equipped with compound parabolic concentrator (CPC). For this purpose, initially a detailed energy balance is carried out to get a thermal model for the system and as the result analytical expressions are p...

In this paper, a nonlinear model associated to the fast switching on-off solenoid valve and pneumatic cylinder was dynamically presented. Furthermore, an investigation into the electrical, magnetic, mechanical and fluid subsystems are made. The characteristics of electromagnetic dynamics are thermally

In this article, a comparative study is carried out between two equations for the exergy efficiency of photovoltaic thermal (PV∕T) air collectors; the first equation is based on net output exergy and the second equation is in terms of exergy losses. The exergy efficiency equation parametrically is dependent on thermal and electrical parameters of P...

In this article, the optimum operating mode of a solar photovoltaic/thermal (PV/T) air collector in terms of exergy losses is obtained. An experimental setup for a typical PV/T air collector is built to measure its thermal and electrical parameters, experimentally. A computer simulation program based on improved thermal and electrical models is als...

In this article, the experimental exergetic performance assessment of a solar photovoltaic thermal (PV/T) air collector is carried out. An experimental set-up for a PV/T air collector is built to measure its thermal and electrical parameters. A detailed energy and exergy analysis is fulfilled to calculate the thermal and electrical parameters, exer...

In this paper, an exergetic optimization has been developed to determine the optimal performance and design parameters of a solar photovoltaic thermal (PV/T) air collector. A detailed energy and exergy analysis has been carried out to calculate the thermal and electrical parameters, exergy components, and exergy efficiency of a typical PV/T air col...

In optimization of thermodynamic cycles, it is appropriate for the economic and environmental aspects to be considered simultaneously. The sum of the fuel and investment cost flowrates is known as thermoeconomic objective function. A new objective function, known as a thermoenvironomic objective function, is obtained by integrating the environmenta...

In this paper, an attempt has been made to obtain nonsensitive solutions in the multi-objective optimization of a photovoltaic/thermal (PV/T) air collector. The selected objective functions are overall energy efficiency and exergy efficiency. Improved thermal, electrical and exergy models are used to calculate the thermal and electrical parameters,...

In large thermal systems, which have many design variables, conventional mathematical optimization methods are not efficient. Thus, exergoeconomic analysis can be used to assist optimization in these systems. In this paper a new iterative approach for optimization of large thermal systems is suggested. The proposed methodology uses exergoeconomic a...

In this paper, an attempt is made to evaluate the exergetic performance of a solar photovoltaic thermal (PV/T) air collector. A detailed energy and exergy analysis is carried out to calculate the thermal and electrical parameters, exergy components and exergy efficiency of a typical PV/T air collector. Some corrections are done on related heat loss...

In this article, an attempt has been made to investigate the exergetic performance of a solar photovoltaic (PV) array. A detailed energy and exergy analysis has been carried out to calculate the operating and electrical parameters, exergy destruction components, and exergy efficiency of a typical PV array. The operating and electrical parameters of...

In any energy system that produces work, heat and so on, disposal remaining flows of matter or energy, which are called residues, will appear. In the exergoeconomic analysis of these systems, one of the complex problems is residues cost allocation in a rational way. Two more important criteria of the residues cost allocation are distribution of the...

The optimum number and locations of heaters over the heater surface of a cubic radiant oven are optimized by using the genetic algorithm of searching. The objective of the problem is to produce the uniform temperature and heat flux distributions over the design surface. The wall surfaces of the oven are subdivided into surface elements and the net...

In this paper, an attempt is made to investigate the thermal and electrical performance of a solar photovoltaic thermal (PV/T) air collector. A detailed thermal and electrical model is developed to calculate the thermal and electrical parameters of a typical PV/T air collector. The thermal and electrical parameters of a PV/T air collector include s...

Optimization is one of the most interesting and essential subjects in the design of energy systems. In the present work, a new iterative approach for the optimization of complex thermal power plants based on the exergoeconomic analysis and the structural optimization method is proposed. Exergoeconomic analysis is used to determine the sum of the in...

In this paper, an attempt is made to investigate the exergetic performance of a solar photovoltaic (PV) array. A detailed energy and exergy analysis is carried out to evaluate the electrical performance, exergy components and exergy efficiency of a typical PV array. The exergy efficiency of a PV array obtained in this paper is a function of climati...

An exergetic optimization is developed to determine the optimal performance and design parameters of a solar photovoltaic (PV) array. A detailed energy and exergy analysis is carried out to evaluate the electrical performance, exergy destruction components, and exergy efficiency of a typical PV array. The exergy efficiency of a PV array obtained in...

In this paper multi-objective genetic algorithms are employed for Pareto approach optimization of ideal Turboshaft engines. In the multi-objective optimization a number of conflicting objective functions are to be optimized simultaneously. The important objective functions that have been considered for optimization are specific thrust 0 (/) & F m ,...

a b s t r a c t In this paper, an exergetic optimization of flat plate solar collectors is developed to determine the optimal performance and design parameters of these solar to thermal energy conversion systems. A detailed energy and exergy analysis is carried out for evaluating the thermal and optical performance, exergy flows and losses as well...

This study presents a fast and straightforward algorithm for inverse estimation of transient powers of heaters placed on the heater surface of a radiant oven to produce the desired uniform temperature and heat flux distributions over the product surface. The aim of the problem is to optimize the design of an oven used in heating processes such as d...

In this paper, an exergetic optimization of the solar air heater is developed. For this means, an integrated mathematical model of thermal and optical performance of the solar heater is derived. The most geometric parameters and operation conditions are considered as variables in this analysis. Some correlations for exergy efficiency of heater comp...

In this research, the sensitivity analysis is applied to an electrohydraulic servovalve which is a nonlinear system. This system sensitivity study differs from previous studies by considering the dynamic behaviour and nonlinearity of the system performance. Different sensitivity analysis methods are compared to each other by studying the sensitivit...

Thesis (M.Eng.)--Concordia University, 1987. Bibliography: leaves 191-202. Microfiche.

Thesis (Ph. D.)--University of Ottawa, 1999. Includes bibliographical references.